Silicon Extraction Methods from Recycled Solar Cells

A flotation process for recovering silicon from diamond wire cutting waste slurry through selective flotation of silicon particles. The process employs a modified silicon surface that enhances the separation efficiency through selective adsorption of collectors like dodecylamine, which improves hydrophobicity. The modified silicon particles, now with enhanced surface properties, are selectively retained during flotation, while the filter cake is processed to remove impurities. This method achieves a silicon recovery rate of 98.2% through a single-step flotation process, addressing environmental and production challenges associated with diamond wire cutting.

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A physical recycling method for waste silicon photovoltaic laminates that effectively separates silicon chips and glass panels while minimizing environmental risks. The method employs a combination of liquid nitrogen immersion, mechanical removal, and mechanical friction to recover valuable materials from the laminates. The process involves heating the laminates to 350-450°C to decompose the EVA and PET layers, followed by controlled mechanical removal and mechanical friction to separate the silicon chips from the glass and backplane components. This approach enables complete silicon chip recovery while maintaining the integrity of the glass and backplane materials, significantly reducing the environmental impact of traditional recycling methods.

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A method for efficiently concentrating valuable materials from solar cell structures by combining heat treatment, crushing, classification, and sorting. The process involves heat-treating the solar cell structure at high temperatures (1,000°C or higher), followed by crushing and sorting to separate the material into distinct grain sizes. The crushed material undergoes further processing, including classification and sorting, to separate the high-grade metallic silicon from other components. The concentrated silicon can then undergo additional processing steps, such as refining and purification, to achieve high purity levels.

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A method for recycling photovoltaic modules by using a wet purification process to extract silicon from the module structure. The process involves sequential alkali cleaning, pickling, and drying steps to remove contaminants and silicon residue from the module's backplate, glass, and frame. The silicon is then extracted through the wet purification process, which uses a combination of alkali and acid solutions to dissolve and separate the silicon from other impurities. The extracted silicon is then purified further through multiple rinses and drying steps before being processed into high-purity silicon.

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A method for recycling silicon photovoltaic cells from tandem solar cells, achieving complete removal of perovskite layers without chemical reactions with perovskite components. The method involves a thermal separation and chemical cleaning process that selectively dissolves the perovskite sub-cells while preserving the silicon substrate. The perovskite is extracted through organic solvents, and the resulting silicon substrate is then processed for further use in solar cells or other applications.

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A novel method for recycling silicon materials from solar cells that addresses the challenges of current recycling processes. The method involves a multi-step process that separates and purifies silicon from the solar cell components. The process begins by removing the glass and metal components, followed by crushing the remaining silicon material into fragments. These fragments are then mixed with a surfactant and further processed to separate the silicon from the other materials. The purified silicon is then refined to produce high-purity silicon ingots. This approach enables the recovery of valuable silicon components while minimizing the generation of hazardous materials during the recycling process.

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A novel method for efficient and environmentally friendly silicon and silver recycling from waste solar panels. The process utilizes a molten alkali leaching method to selectively extract and recover silicon and silver from the solar panel's metallurgical-grade silicon (MG-Si) and metallurgical-grade silicon (MG-Si) wafers, respectively. The recovery process involves a controlled temperature and salt composition in the molten salt, enabling rapid separation of the target materials from the remaining photovoltaic material. The method achieves higher purity silicon and silver recoveries compared to conventional recycling methods, with a simplified preparation process and lower environmental impact.

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A method for extracting valuable components from photovoltaic panels through controlled thermal disassembly, enabling the recovery of reusable materials. The process involves cooling the photovoltaic panel's glass structure with liquid nitrogen while maintaining structural integrity, followed by mechanical separation of the glass and aluminum frame. The cooled glass is then processed to remove contaminants and prepare it for further processing into raw materials. The aluminum frame is then extracted and processed into individual profiles, which can be used in new photovoltaic panels or other products.

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A green and efficient method for the separation and recycling of photovoltaic modules containing silicon-containing waste. The method involves pyrolyzing the core components to produce glass, solder ribbons, and battery sheets, followed by cleaning, vacuum drying, and recycling of these residues. The process then converts the cleaned battery sheets into a nitric acid solution containing silver nitrate, aluminum nitrate, and impurities, followed by the controlled leaching of silver and aluminum to produce high-purity metal ions. The recovered metal ions are then converted into usable form through selective precipitation, ion exchange, or electrolysis.

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A novel method for efficient and environmentally friendly silicon recycling from solar cells. The process involves a two-stage treatment sequence: first, the solar cells are soaked in a sodium hydroxide solution to remove surface layers, followed by a mixed acid treatment of nitric acid and hydrofluoric acid. This sequential approach enables the recovery of both silicon and valuable metals while minimizing waste generation. The method achieves high silicon recovery rates, especially for silicon-containing solar cells, and presents a practical alternative to traditional acid-based recycling methods.

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A recycling method for photovoltaic modules that achieves high-quality silicon recovery through controlled laser cleaning and etching. The method employs laser cleaning to remove glass and chip residue, followed by sequential etching steps to remove the silicon wafer and aluminum back electrode. The laser cleaning process uses different power settings to prevent chip damage while ensuring complete separation of the components. The etching process employs controlled etching parameters to remove the remaining aluminum and silver electrodes. This approach enables the selective recovery of high-quality silicon wafers while preserving the integrity of the glass plates.

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A method for efficient and environmentally friendly recycling of photovoltaic module components through chemical treatment. The method involves the recovery of silicon, silver, and aluminum from decommissioned photovoltaic modules through anhydrous sulfuric acid treatment, followed by selective enrichment of these metals through chemical separation. This process enables the recovery of valuable metals without requiring complex acid leaching processes or high-energy thermal treatments. The recovered metals can be used directly in the production of new photovoltaic cells or other semiconductor applications, while minimizing environmental impact.

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A pyrolysis-based recycling system for photovoltaic cell assemblies that utilizes controlled thermal decomposition to recover valuable materials. The system comprises a pyrolysis device, separation device, and gasification device that work in tandem to convert photovoltaic cell components into pure silicon and other valuable materials. The pyrolysis process involves heating the cell assembly in a controlled environment to initiate decomposition, followed by separation of the resulting materials through various techniques. The gasification device further processes the separated materials to produce a clean and pure silicon product.

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A method for recycling photovoltaic modules through a single-step process that efficiently recovers all components, including glass, plastic, aluminum, copper, silver, and silicon. The method involves thermal cutting to separate components, followed by crushing and sorting of cells to obtain tinned copper strips and cell powders. The copper strips are then processed using acid leaching to extract silver, while the silicon powder is purified through a combination of acid leaching and chemical treatment. The purified components are then combined to form a new product with high value-added properties.

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Method for recycling photovoltaic modules by selectively separating and recovering valuable components through electrostatic separation. The method involves mechanically separating the module's sandwich structure, shredding the resulting particles, and then using an electrostatic separator to separate the particles into two distinct fractions. The first fraction contains less than 5% polymer particles and is substantially free of glass particles, while the second fraction contains higher polymer content. The fractions are then further processed through multiple electrostatic separations, with the second fraction being recycled back into the process.

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Method for producing high-purity silicon nanopowder from solar panel waste, followed by its use as a negative electrode material for lithium-ion batteries. The process involves rapid cooling of the solar panel to separate its components, followed by the recovery of silicon scrap. The silicon is then processed using vacuum thermal plasma to produce high-purity silicon nanopowder. This nanopowder is then used as a negative electrode material in lithium-ion batteries, offering a significant environmental and economic alternative to traditional battery materials.

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Separating and recycling silicon wafers from photovoltaic modules through a novel pulsed airflow sorting process. The method employs a combination of mechanical and airflow separation techniques to isolate silicon wafers from photovoltaic module components, particularly from glass fragments and cell sheets, after the organic layer is removed. This enables efficient separation and subsequent purification of silicon wafers, which are typically recovered as valuable material in the photovoltaic recycling process.

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A novel method for producing high-purity silicon from solar waste by selectively leaching metals from silicon waste using a controlled acid dissolution process. The method involves crushing solar cells, followed by a multi-stage acid leaching process where specific metals like aluminum, silver, tellurium, barium, lead, bismuth, vanadium, zinc, strontium, calcium, and iron are selectively dissolved from the silicon. The leaching process is optimized for each metal type using different acid concentrations and leaching times, followed by solid-liquid separation and purification steps. The resulting purified silicon can be further processed to achieve even higher purity levels.

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A low-cost method for recycling waste silicon from solar panels by pyrolysis and grinding of waste silicon, specifically targeting EVA contamination. The process involves cutting the silicon into smaller pieces, grinding them into a fine powder, and then applying controlled low-temperature pyrolysis to thermally decompose the EVA while simultaneously grinding the silicon to produce high-purity powder. This integrated approach eliminates the need for multiple chemical treatments and high-temperature melting, significantly reducing the environmental impact and energy requirements of the traditional recycling process.

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A method for recycling photovoltaic modules that enables complete recovery of aluminum, silver, and silicon wafers while maintaining their photovoltaic properties. The recycling process involves a two-step approach: first, dismantling and heat treatment of the module to separate the battery sheet and other components, followed by confinement heat treatment of the battery sheet to achieve a uniform temperature across the entire sheet. This step preserves the structural integrity of the aluminum frame, junction box, and tempered glass while achieving a uniform temperature across the entire sheet. The confinement heat treatment process is optimized to preserve the silicon-aluminum alloy layer and its microstructure. The resulting silicon wafers are then texturized to create a nano-textured surface with unique properties that enhance light absorption and reflectivity.

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